Our previous research has demonstrated that while destruction of the rat's primary visual neocortex may disrupt a learned brightness discrimination, the neurological memory engrams associated with the behavior are spared. Moreover, in certain instances, these memory engrams may influence the progress of postoperative recovery of visual functioning. The presently proposed research utilizes drugs, combined lesion techniques, and postoperative training procedures to attempt to determine how this influence occurs and how it might be increased to facilitate recovery of function after brain damage.